The Otter (Lutra lutra) Situation in Latvia and Sweden Related to PCB and DDT Levels.
Since the 1950s some European otter populations have declined dramatically. There are however significant differences in the otter population density between different areas. Many suggestions have been presented to explain the population decline and the effects of PCB is one of these. The aim of this study was to compare the concentrations of PCB and sDDT in otter, fish and amphibians from Latvia with Swedish data and available information from the literature. Samples from two areas in Latvia and one area in Sweden were analyzed. It was shown that the concentrations of PCB in otter, fish and amphibians from Latvia were lower than reported concentrations in otter and fish from other areas in Europe. In the light of the high density otter population in Latvia and low concentrations of PCB in Latvian biota, this study supports the hypothesis that the effects of PCB constitutes one of the most important agents in explaining the decline of otter populations in Europe.